The present invention relates to a reclining angle adjustment device for adjusting the angle of inclination of the seat back of a reclining seat in a motor vehicle, i.e., the reclining angle of the reclining seat.
There are known reclining angle adjustment devices in which the reclining angle is finely adjusted by means of a planetary gear mechanism composed of an angularly movable shaft, an outer gear, and an inner gear, and the reclining angle is roughly adjusted by a pawl and ratch mechanism. Such reclining angle adjustment devcies, especially designed for a compact size and improved operability, have a release lever supported on the angularly movable shaft.
The reclining angle adjustment devices include a spring for normally urging the release lever in one direction to keep the pawl in engagement with the latch. Under the biasing force of the spring, there is produced a large force acting between the release lever and the shaft when the release lever is not operated. Therefore, the release lever and the shaft as they are in contact with each other are subject to an increased resistance. This increased resistance requires a large force to be applied to operate a control handle when the reclining angle is to be finely adjusted.